Silicene, a two-dimensional honeycomb lattice of silicon atoms with similarities to graphene, has attracted interest both in terms of the fundamental physics behind its properties and new technologies that might exploit them. However, a stable form of the material has proved elusive, making it hard to pin down its characteristic properties and possible applications.
The two-dimensional silicon can be grown epitaxially and investigated in high vacuum. In the past, it was not expected to survive isolation from its parent substrate or exposure to air, and therefore, silicene transistors were not envisaged. However, thick multilayer silicene films have been currently demonstrated to be stable for at least 24 hours in the air.
While such a feat is exciting and will allow scientists to further probe the material and exploit the properties that have made silicene a promising material in the electronics industry, the silicene films can only be stable for 24 hours in the air thereby preventing the silicene from being utilized in a transistor device. The pristine properties of two-dimensional materials, such as silicene, are not being preserved from degradation when exposed to air. As a result, there is not currently a means for effectively protecting highly air-sensitive two-dimensional Xene materials, such as silicene, germanene, stanene and phosphorene, during the transfer and device fabrication.